Electronic devices support touch-type input devices such as a touch screen, a touch pad, or a touch key as part of a user interface (UI). These touch-type input devices are implemented in various methods such as a capacitive, resistive, infrared, or ultrasonic methods. For example, a capacitive touch input method may recognize touch by determining a change in capacitance, which occurs by a conductive object, such as, for example, a user's finger or a stylus pen.
However, the capacitive touch input method may malfunction if there is a factor that changes a capacitance on the conductive object (for example, a touch object). For example, when a finger stained with sweat or water contacts the touch screen, or a user wears gloves covering the fingers while contacting the touch screen, a capacitive touch input device may not correctly recognize the contact of a touch object, or may recognize unintended touch coordinates as a contact point. Additionally, a touch input method such as a resistive, infrared or ultrasonic method may malfunction when a touch object such as a finger is stained with water or sweat, or a user wears gloves cover their fingers.